C10 Build - what's the latest/greatest swap for best mileage?

[heynow14]

Hi guys -

I'm in the planning stages for a C10 and I'm looking for advice on a swap to get best mileage and drivability/reliability. I'm not overly concerned with power or towing/carrying capacity etc...I've got my '69 Camaro to be the trouble maker so I basically just need this truck to be a stand-in for a new truck...I have ZERO interest in a new truck or a new truck payment...

Please let me know what swaps you've done and what REAL mileage and daily driving action you're seeing.

Thx much for all of your help!

Nick

[67_C-30]

Originally Posted by heynow14

Hi guys -

I'm in the planning stages for a C10 and I'm looking for advice on a swap to get best mileage and drivability/reliability. I'm not overly concerned with power or towing/carrying capacity etc...I've got my '69 Camaro to be the trouble maker so I basically just need this truck to be a stand-in for a new truck...I have ZERO interest in a new truck or a new truck payment...

Please let me know what swaps you've done and what REAL mileage and daily driving action you're seeing.

Thx much for all of your help!

Nick

First of all, welcome to the board!

Secondly, you have this in the wrong section, so that has probably cut down on responses.

But for your question, the best combo for fuel mileage would be a 6.2 diesel with 700R-4, but I doubt you're thinking diesel. As far as readily available gassers, I'd think a 4.8L/4L60E combo out of a 99 - up Chevy truck would probably be the most economical package, and would still make nearly 300 HP. As far as carb'd engines goes a 307 or a maybe even a 283 with a Q-jet and a 700R-4 would be probably tops in economy but would be mediocre on power 200 - 220 HP.

Now, this part is just my opinion and commentary, so take it with a grain of salt! I am in same boat as you in regards to new trucks. I drive old trucks because I want to. I recently sold a Z71 that I bought new because I put 3000 miles on it 4 years. Nothing about new trucks excite me when you get past the new car smell. I never say never, but I'm fairly certain I've never buy another new truck only to have it decrease in value by the minute. I have yet to lose money on an old truck.

Being that I am (and plan to continue to be) without a new truck payment, I care less about fuel mileage than I used to. That doesn't mean I want to get 10 MPG, but I care if i don't get 20+. It's easy to get 300+ HP with a good combination of parts on an carb'd old 350 with decent heads and with an OD trans, it will cruise out on the interstate and have enough power to be fun to drive. That is exactly what I'm building for my '68, and I will drive it anywhere I want to go.

[heynow14]

Thx for your reply. I'll post in the engine forum...I'm guessing that's the best place.

I've got a zz4 in my camaro that I'm thinking I should swap into the truck and then slap in a OD auto with a grannie rear end gear for optimal mileage.

Next question then: is a 700r4 the best auto option for a dd seeking best mileage?

Thx again,
Nick

[Xeen]

Originally Posted by heynow14

Thx for your reply. I'll post in the engine forum...I'm guessing that's the best place.

I've got a zz4 in my camaro that I'm thinking I should swap into the truck and then slap in a OD auto with a grannie rear end gear for optimal mileage.

Next question then: is a 700r4 the best auto option for a dd seeking best mileage?

Thx again,
Nick

Like you said you have your 69 Camaro when you feel like blowing off some steam so there is really no reason to build a beast motor for your truck.

My advice is to find a low milage Vortec 5.3L/4l60e combo for it and enjoy the hell out of it, all the aftermarket support is there and you can stab and go.
See my build thread for some insight into the swap, I am still in the process of completing mine and there is some really good information in there to help you avoid the pitfalls that I had to deal with which will make yours alot smoother and quicker.

[kcsa75]

Hey there heynow14,

Welcome to the forum. C'mon in and look around. You're among friends here.

I'm moving your thread to the main 67-72 board. More guys will see and you should get plenty of responses.

If it were me, I'd be looking at a 250 or 292 straight six. Simple, dependable and should get you decent mileage.

Good luck.

[brad_man_72]

5.3 4l60e 3.73s 17mpg pulling my boat 70mph. Plenty of fun, cheap easy and proven swap, runs the quarter in 14.7 seconds.

If money is no object you could probably swap the entire drivetrain from a new prius.
If you really don't care about power a diesel from a forklift would probably get really good mileage.
If you just want to save money a tune up on whatever you have is usually the cheapest route, depending on how much you drive an engine swap can take a long time to pay for itself.

[DGulliver]

The injected Vortec 5.3's are pretty reliable and arguably less fiddly than a carb'd engine. Opinions may vary on that, but who cares about gas mileage??

[67_C-30]

Originally Posted by DGulliver

The injected Vortec 5.3's are pretty reliable and arguably less fiddly than a carb'd engine. Opinions may vary on that, but who cares about gas mileage??

Only to people that don't know how to tune a carburetor!

Seriously though, the 5.3's are great engines, but speaking from experience, the 4.8 is not a bad choice either. They make great power (285 net HP) for a 293 cu in engine. That is what the 90's LT1 350's in the Camaros made. They are usually cheaper too, because most people want the 5.3 or 6.0.

Just something to keep in mind for a good blend of power and economy.

[Motoxrrar]

I would have to agree with my experience gen 4 4.8L with 4L80e in mine and great gas milage. I bought mine for 500$ really cheap spent 400$ on my 4L80e and 600 on wiring and programming. Wonderful swap. Not many challenges besides using stock gauges. But I just made a few of my own solutions. I don't really like using a bunch of adapters.

Then if you need more power just throw a blower on it. 400hp easy.

[jks67ss396]

where in orange county?

I have a 71 C10 that i just put a 5.3/4l60 in and ive got a 67 camaro that im doing a 6.0 with a big BW turbo

i love the 5.3

[MARKDTN]

First choice 4.8/4L60E

Second choice Tuned Port 350/700R4.

My '83 K20 went from 14mpg to 17 just by swapping in a complete '91 TPI from a Corvette. It has a 700R4 and 3.42 gears.

[chuckmc8]

No question- 4.8 or 5.3 with 4l60E with 3:42 (custom ratio for our trucks) or 3:73. These get good mileage and run great. I usually let (sane) skeptics drive one of mine and they are instant believers :-)

[heynow14]

Thx to all for the replies. Seems like the 4.8 is getting votes...

I'm torn since I have a zz4 in the Camaro that I could swap into a truck and then just build an LS for the camaro. My dumb-dumb calculations tell me that it'll take about 3-4 years to pay for a ls swap versus using the zz4....so not sure. Perhaps the zz4 and a 700r4 with a 3.08 rear will net me around 20 hwy.

JKS67ss396-
I'm in yorba Linda, CA. If you'd be up to it, I'd love to check out your truck...and your camaro... . Let me know if you're in for a visit....perhaps a beer...

Thx,
Nick

[bshepherd1]

4bt cummins and a five speed will get you around 25-30 mpg and still tow and haul

[jks67ss396]

Hey Nick

Im in Fullerton My camaro is not getting too much attention since my little guy was born, but ill be getting back on it soon. everything is mocked up now, but i want to change a few things. Definitely, get together sometime. PM me with some weekends that youre free.

As for the 4.8, i had a 4.8 in a 2005 silverado, and while it did the job, it wasnt too fun and it didnt get that good of mileage. now, that truck was a lot heavier and 4x4, so maybe a 4.8 is right at home in these trucks.

I went with a 5.3 for that very reason... cause i remembered the 4.8

i have 3.73 posi in my truck, changed from a 3.08. was thinking of 3.42, but wasnt sure id be happy with it, so i went up to a 3.73. may tow a bit too

with the 4l60 (same ratios as the 700r4 i believe), the 3.08 was WAY too high. the 5.3 felt like it had no guts. so a 4.8 with a 700r4 and 3.08 is gonna feel real crappy.

might even kill your mpg because the truck will be lugging in 4th OD with a 3.08

so with a 4l60/4l80, at least go with 3.42. maybe a 3.55 or a 3.73

as for my truck, i hate the dbw delay, but im about to try to tune some of that out with hptuners, but we can go for a ride if you like

[StoningtonQB]

You'd be surprised what a 1406 Edelbrock can do on a regular 350. Your mileage will be better than stock!

[Motoxrrar]

The 4.8 and 5.3 are actually the same bore size. 5.3 just has a different stroke. I had a 4.8 and a 5.3 milage wise 4.8 will be better. But stock power 5.3 had like 50 more hp. But if your looking for fun the 4.8 holds boost better. Supercharger, pro charger, turbos, they are cheap enough to put down a lost of fun.

[kentucky_smith]

I've actually been surprised at how easy on gas my 307 with 3.07 gears and 350THM has been. Does much better than my 2001 5.9 Ram and 2004 F150--much lighter too.

[jks67ss396]

when i bought my truck, it had a 283 th350 and 3.08s and the guy claimed he was getting close to 20mpg, but that was a little 2barrel carb and man, that thing took some time to get up to 60mph.

musta been into weight savings too... he made the truck lighter by leaving bolts out of the motor mounts and frame stands...

[heynow14]

Weight savings...motor mounts are nice place to remove parts. I found a piece of plexiglass used as a body shim on my Camaro...pretty awesome what idiots come up with over the decades...

[GRX]

Dropping in a 250 or 292 straight-6 won't increase mileage, that is a myth. Best thing you can do is add mast & sail.

[hugger6933]

Keeping in mind I'm not offering this as a for sale item, that and I'm half way across the country I'd say 4.8/5.3 with the 4l60 combo. I sold a 4.8 with the trans and all wiring and acc pcm everything [i sell them like I would like to buy them] for just a tick under $1000 for all. the 5.3 would be a little higher and the 6.o's a little higher still. They would make a great platform for what you want. Jim

[67_C-30]

Originally Posted by Motoxrrar

The 4.8 and 5.3 are actually the same bore size. 5.3 just has a different stroke. I had a 4.8 and a 5.3 milage wise 4.8 will be better. But stock power 5.3 had like 50 more hp. But if your looking for fun the 4.8 holds boost better. Supercharger, pro charger, turbos, they are cheap enough to put down a lost of fun.

It was more like 10 - 15 HP difference depending on year model.

The first year of these (1999), the 4.8L was rated at 270, and the 5.3L was rated at 285. They both increased through the the years.


These were the ratings from 2010.

Transmission: Automatic
Drivetrain: Rear Wheel Drive
MPG: 14 City / 19 Hwy
Engine: Gas/Ethanol V8 4.8L/293
Horsepower: 302 @ 5600
Torque: 305 @ 4600 4.8L/293

Transmission: Automatic
Drivetrain: Rear Wheel Drive
MPG: 15 City / 21 Hwy
Engine: Gas/Ethanol V8 5.3L/323
Horsepower: 315 @ 5200
Torque: 335 @ 4000 5.3L/323

[67_C-30]

I can add that a 4.8L 5 speed will wax a 5.3L automatic every time if they are both stock. Been there, done that many times!